Catheters are tools commonly employed to help diagnose and treat medical conditions by allowing access to remote locations within a living body. A wide range of medical procedures can be performed with a catheter, such as imaging, angioplasty and the release of therapeutic agents into the body. Catheters provide particular advantages when used to gain access to regions of the body otherwise reachable only with invasive surgery.
Catheters are most often used in diagnosing and treating atherosclerosis and other arterial diseases with procedures such as angioplasty. In angioplasty, a balloon located on a catheter is placed within a constricted artery and inflated so as to break apart occlusive plaque and restore normal blood flow to the artery. In order to place the balloon within the constricted artery, the catheter is typically advanced through various body lumens, such as arteries and blood vessels within the circulatory system. By this nature, navigation through these lumens is generally unrestricted.
However, catheters are frequently adopted to navigate to other regions of the body, outside the circulatory system. In these cases, access can be restricted by one or more body tissues. In many cases the only way to reach the desired location is to advance the catheter through the obstructing tissue. Various systems and methodologies have been developed to penetrate the obstructing tissue. For instance, some systems rely on piercing instruments such as a needle, located within the catheter, to pierce the tissue and create an opening through which the catheter can be advanced. Other systems rely on a drilling instrument, where an actual drill bit is used to penetrate the material. These systems are very inaccurate and can easily damage other tissues within the body.
For instance, these systems typically run the risk of “overshoot,” which occurs when the various instrument advances further than intended, either too far into the body tissue or entirely through the body tissue and into a second tissue. These instruments also run the risk of damaging body tissue by mere incidental contact with another tissue. In addition, these systems are often encumbered by the penetrating instrument, which must be incorporated into the catheter along with the other medical or imaging devices already in place. Furthermore, these instruments are effectively blind when penetrating a tissue, in which case penetration can occur directly into a blood vessel or other vital organ resulting in a serious health risk to the patient.
Thus, there is a need for improved systems and methods of penetrating internal body tissues.